Cell Organelles
What is the main difference between a eukaryotic and a prokaryotic cell?
Prokaryotic cells do not have a true nucleus.
What is the purpose of cholesterol in the cell membrane?
Helps to maintain fluidity at high and low temperatures.
Describe Osmosis
The diffusion of water down its concentration gradient.
What are the 3 types of solutions?
1. Isotonic
2. Hypertonic
3. Hypotonic
What is the powerhouse of the cell and why?
The mitochondria because it produces ATP.
What are the 3 organelles unique to animal cells?
Lysosomes
Centrosomes
Flagella
State the 4 parts of a phospholipid.
1. Phosphate group
2. Glycerol
3. Hydrophilic head
$. Hydrophobic tails
IS facilitated diffusion active or passive transport, and why?
Facilitated diffusion is passive transport, because it does not require energy to move things down their concentration gradient.
What solution increases the turgor pressure of a plant cell? And why?
Hypotonic, because water will fill the central vacuole and increases turgor pressure.
The size of a cell will dictate what?
Its function.
Where is ribosomal RNA synthesized?
the nucleolus
What determines the hydrophobic or hydrophilic nature of a protein?
Determined by the "R Group" or variable side chain of the protein.
Polar side chain = hydrophilic
nonpolar side chain = hydrophobic
What is the flow direction of ions determined by?
the electrochemical gradient
Water moves from an area of ____ solute concentration to an area of _____ solute concentration.
LOW solute concentration to HIGH solute concentration.
What is the ionization constant for NaCl?
NaCl will ionize into Na+ and Cl-. Therefore, the ionization constant is 2.
What are the folds on the mitochondria called, and what is their main purpose?
The folds are called cristae, and their main function is to increase surface area within the mitochondria.
Carbohydrates are found on the outside of the cell membrane. What is their main purpose, and what two main categories of them are there?
The main function is to serve as an identification marker for cell-to-cell recognition. The two main categories of them are glycoproteins and glycolipids.
What are aquaporins and are they considered active or passive transport?
specialized channel proteins for water, and they are a type of facilitated diffusion, therefore, they exhibit passive transport.
I am mixing my solution in an open beaker with pure water. What is the pressure and solute potential? (With units)
The pressure potential in an open air environment is 0 MPa or 0 bars.
The solute potential of pure water is 0 MPa or 0 bars.
What is cytolysis?
When an animal cell bursts in a hypotonic solution, due to an influx of water entering the cell.
(must note animal cell to get points)
1. double membrane
2. ribosomes
3. circular DNA
4. capable of functioning on their own
What is osmotic lysis? And what is used to help prevent it?
Osmotic lysis - cell bursting when excess water goes into the cell. The cell wall is used to protect plant cells from this.
What is the net charge of the cytoplasm when looking at a sodium-potassium pump? Why?
(Hint: looking for the amount of ions on each side)
3 Na+ ions are pumped out of the cell
2 K+ ions are pumped into the cell
Results in a +1 net charge to the extracellular fluid
A plant cell has a concentration of 0.5 nM NaCl and is placed in a flask with a 0.9 nM NaCl solution. What is the solution in relation to the plant cell and what will happen to the plant cell?
The solution is hypertonic, water will flow out of the plant cell and the cell will most likely exhibit plasmolysis.
Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. What is one major advantage for eukaryotes to have membrane-bound organelles internally?
Organelles isolate specific activities, and increase metabolic efficiency.
or
Compartmentalization of jobs inside the cell leads to higher efficiency of intra-cellular jobs.